scholarly journals Galactose-positive adjunct cultures prevent gas formation by Paucilactobacillus wasatchensis WDC04 in a model gas production test

2021 ◽  
Author(s):  
Ireland R. Green ◽  
Craig J. Oberg ◽  
Jeffery R. Broadbent ◽  
Randall K. Thunell ◽  
Donald J. McMahon
Keyword(s):  
Gas Production ◽  
Production Test ◽  
Adjunct Cultures ◽  
Gas Formation

Diet effects on methane production by goats and a comparison between measurement methodologies

2008 ◽  
Vol 146 (6) ◽  
pp. 705-715 ◽  
Author(s):  
R. BHATTA ◽  
O. ENISHI ◽  
N. TAKUSARI ◽  
K. HIGUCHI ◽  
I. NONAKA ◽  
...  
Keyword(s):  
Small Ruminants ◽  
National Research Council ◽  
Mean Value ◽  
Open Circuit ◽  
Gas Production ◽  
Mitigation Strategies ◽  
Production Test ◽  
Gross Energy ◽  
Nutritive Composition

SUMMARYA series of studies were carried out to measure the methane (CH4) production by Japanese goats fed 19 different diets (D1–D19) varying in nutritive composition in the open circuit respiration chamber (RC) and to compare them with CH4 estimated by the in vitro gas production test (IVGPT). Adult Japanese goats (>2 years old) with a mean body weight of 26±5·4 kg were used in these experiments. Each diet was fed to four randomly selected goats and feeding was carried out at 1·1 maintenance (M) as per National Research Council (NRC) (1981) for goats. Average CH4 emission by goats in the RC ranged from 0·23 to 0·39 (mean value 31 ml/g dry matter intake (DMI)); when it was expressed as a proportion of gross energy or, with methane conversion rate (MCR), it ranged from 5·0 to 8·2, with an average of 6·6. Incorporation of by-products like sweet potato vine silage (SPVS) (P=0·016), dried pumpkin (P=0·052) and brewers' grain in the diet suppressed (P<0·01) methanogenesis in goats, when compared with that of standard farm diet (D1). The CH4 output measured in the RC was very close to that estimated from the gas collected after 24 h and higher after 48 h of in vitro incubation. Although composition of the diets' acid detergent fibre (ADF) had a significant effect on methane emission, methane output estimated by IVGPT was very close to that measured in the RC demonstrating that this system could be used to estimate the CH4 production potential from diets in preparing a database and also in the planning of mitigation strategies in small ruminants to improve their performance as well as to reduce greenhouse gas emissions.

scholarly journals Analisis dan Optimasi Pengaruh Suhu Gas Umpan Pada Kinerja Acid Gas Removal Unit

2021 ◽  
Vol 1 ◽  
pp. 67-74
Author(s):  
Iwan Febrianto ◽  
Nelson Saksono
Keyword(s):  
Simulation Model ◽  
Flow Rate ◽  
Gas Production ◽  
Gas Content ◽  
Production Test ◽  
Reservoir Pressure ◽  
Gas Temperature ◽  
Separation Unit ◽  
Acid Gas ◽  
Gas Removal

The Gas Gathering Station (GGS) in field X processes gas from 16 (sixteen) wells before being sent as selling gas to consumers. The sixteen wells have decreased in good pressure since 2011, thus affecting the performance of the Acid Gas Removal Unit (AGRU). The GGS consists of 4 (four) main units, namely the Manifold Production/ Test, the Separation Unit, the Acid Gas Removal Unit (AGRU), the Dehydration Unit (DHU). The AGRU facility in field X is designed to reduce the acid gas content of CO2 by 21 mol% with a feed gas capacity of 85 MMSCFD. A decrease in reservoir pressure caused an increase in the feed gas temperature and an increase in the water content of the well. Based on the reconstruction of the design conditions into the simulation model, the amine composition consisting of MDEA 0.3618 and MEA 0.088 wt fraction to obtain the percentage of CO2 in the 5% mol sales gas. The increase in feed gas temperature up to 146 F caused foaming due to condensation of heavy hydrocarbon fraction, so it was necessary to modify it by adding a chiller to cool the feed gas to become 60 F. Based on the simulation, the flow rate of gas entering AGRU could reach 83.7 MMSCFD. There was an increase in gas production of 38.1 MMSCFD and condensate of 1,376 BPD. Economically, the addition of a chiller modification project was feasible with the economical parameters of NPV US$ 132,000,000, IRR 348.19%, POT 0.31 year and PV ratio 19.06.

Mechanical properties of hydrate-bearing turbidite reservoir in the first gas production test site of the Eastern Nankai Trough

2015 ◽  
Vol 66 ◽  
pp. 471-486 ◽  
Author(s):  
Jun Yoneda ◽  
Akira Masui ◽  
Yoshihiro Konno ◽  
Yusuke Jin ◽  
Kosuke Egawa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Nankai Trough ◽  
Test Site ◽  
Gas Production ◽  
Production Test

Comparison of Simplistic and Geologically Descriptive Production Modeling for Natural-Gas Hydrate by Depressurization

SPE Journal ◽  
2019 ◽  
Vol 24 (02) ◽  
pp. 563-578 ◽  
Author(s):  
Yilong Yuan ◽  
Tianfu Xu ◽  
Yingli Xia ◽  
Xin Xin
Keyword(s):  
Gas Hydrate ◽  
History Matching ◽  
Nankai Trough ◽  
Flow Behavior ◽  
Test Site ◽  
Gas Production ◽  
Production Test ◽  
Hydrate Reservoir ◽  
Hydrate Saturation ◽  
Production Modeling

Summary Marine-gas-hydrate-drilling exploration at the Eastern Nankai Trough of Japan revealed the variable distribution of hydrate accumulations, which are composed of alternating beds of sand, silt, and clay in sediments, with vertically varying porosity, permeability, and hydrate saturation. The main purposes of this work are to evaluate gas productivity and identify the multiphase-flow behavior from the sedimentary-complex hydrate reservoir by depressurization through a conventional vertical well. We first established a history-matching model by incorporating the available geological data at the offshore-production test site in the Eastern Nankai Trough. The reservoir model was validated by matching the fluid-flow rates at a production well and temperature changes at a monitoring well during a field test. The modeling results indicate that the hydrate-dissociation zone is strongly affected by the reservoir heterogeneity and shows a unique dissociation front. The gas-production rate is expected to increase with time and reach the considerable value of 3.6 × 104 std m3/d as a result of the significant expansion of the dissociation zone. The numerical model, using a simplified description of porosity, permeability, and hydrate saturation, leads to significant underestimation of gas productivity from the sedimentary-complex hydrate reservoir. The results also suggest that the interbedded-hydrate-occurrence systems might be a better candidate for methane (CH4) gas extraction than the massive hydrate reservoirs.

scholarly journals The degradability characteristics of fifty-four roughages and roughage neutral-detergent fibres as described by in vitro gas production and their relationship to voluntary feed intake

1997 ◽  
Vol 77 (5) ◽  
pp. 757-768 ◽  
Author(s):  
M. Blümmel ◽  
K. Becker
Keyword(s):  
Dry Matter ◽  
Live Weight ◽  
Exponential Model ◽  
Gas Production ◽  
Production Test ◽  
In Vitro Gas Production ◽  
Short Period ◽  
Volume Measurements ◽  
Gas Volume

Fifty-four roughages of known voluntary dry-matter intakes (DMI; range 7·8−35·2 g/kg live weight per d) were examined in vitro in a gas production test. Samples (200 mg) of roughage and roughage neutral-detergent fibre (NDF) respectively were incubated in a mixed suspension of rumen contents for 96 h and the gas volumes recorded after 4,6,8,12,24,30,36,48,54,60 and 96 h. The kinetics of gas production were derived from the volume recordings described by the exponential equation Y=A+B(l—e-ct) where A is the intercept and ideally reflects the fermentation of the soluble and readily available fraction of the feed, B describes the fermentation of the insoluble (but with time fermentable) fraction and c the fractional rate at which B is fermented per h; A+B describes total fermentation. In vitro true dry matter (TD) and NDF degradabilities (NDF-D) after 24 h incubation were also determined. Of the variation in DMI, 75% was accounted for by the in vitro gas production parameters A, B and c in stepwise multiple regressions; 82% of the variation in DMI was explained by the parameters (ANDF+BNDF) and cNDF as obtained from the incubation of roughage NDF. The rate constants (c) were less important than parameters related to the extent of gas production, accounting for only 6·5 (whole roughage) and 4·1% (NDF) of the variation in DMI. There was no statistical advantage in the use of the exponential model describing extent and rate of fermentation over some of the simple gas volume measurements: 75% of the variation in DMI was accounted for by in vitro gas production of whole roughage after 8 h of incubation. On average gas production from NDF measured from 24–96 h accounted for 81% of the variation in DMI. A combination of gas volume measurements after a short period of incubation (4–8 h) with a concomitant determination of NDF-D after many hours (≥24 h) can render NDF preparations and long incubation times redundant. A method is suggested to obtain two results for DMI prediction in one single incubation. Of the variation in DMI 80% was accounted for by the incubation of 500 mg whole roughage when incubation was terminated after 24 h and the residual undegraded substrate quantified.

scholarly journals Engineering nature for gaseous hydrocarbon production

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Mohamed Amer ◽  
Helen Toogood ◽  
Nigel S. Scrutton
Keyword(s):  
Fatty Acid ◽  
Fossil Fuels ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Gas Production ◽  
Single Step ◽  
Short Chain ◽  
Gaseous Hydrocarbon ◽  
Gas Formation

AbstractThe development of sustainable routes to the bio-manufacture of gaseous hydrocarbons will contribute widely to future energy needs. Their realisation would contribute towards minimising over-reliance on fossil fuels, improving air quality, reducing carbon footprints and enhancing overall energy security. Alkane gases (propane, butane and isobutane) are efficient and clean-burning fuels. They are established globally within the transportation industry and are used for domestic heating and cooking, non-greenhouse gas refrigerants and as aerosol propellants. As no natural biosynthetic routes to short chain alkanes have been discovered, de novo pathways have been engineered. These pathways incorporate one of two enzymes, either aldehyde deformylating oxygenase or fatty acid photodecarboxylase, to catalyse the final step that leads to gas formation. These new pathways are derived from established routes of fatty acid biosynthesis, reverse β-oxidation for butanol production, valine biosynthesis and amino acid degradation. Single-step production of alkane gases in vivo is also possible, where one recombinant biocatalyst can catalyse gas formation from exogenously supplied short-chain fatty acid precursors. This review explores current progress in bio-alkane gas production, and highlights the potential for implementation of scalable and sustainable commercial bioproduction hubs.

Characterization of Clostridium spp. Isolated from Spoiled Processed Cheese Products

2006 ◽  
Vol 69 (8) ◽  
pp. 1887-1891 ◽  
Author(s):  
LENA LYCKEN ◽  
ELISABETH BORCH
Keyword(s):  
Cellular Fatty Acid ◽  
Fatty Acid Analysis ◽  
Culture Collection ◽  
Gas Production ◽  
Clostridium Sporogenes ◽  
Source Of Infection ◽  
Gas Formation ◽  
Rdna Sequencing ◽  
High Degree ◽  
Clostridium Spp

Of 42 spoiled cheese spread products, 35 were found to harbor Clostridium spp. Typical signs of spoilage were gas production and off-odor. The identity was determined for about half of the isolates (n = 124) by Analytab Products (API), Biolog, the RiboPrinter System, 16S rDNA sequencing, cellular fatty acid analysis, or some combination of these. The majority of isolates were identified as Clostridium sporogenes (in 33% of products), but Clostridium cochlearium (in 12% of products) and Clostridium tyrobutyricum (in 2% of products) were also retrieved. Similarity analysis of the riboprint patterns for 21 isolates resulted in the identification of 10 ribogroups. A high degree of relatedness was observed between isolates of C. sporogenes originating from products produced 3 years apart, indicating a common and, over time, persistent source of infection. The spoilage potential of 11 well-characterized isolates and two culture collection strains was analyzed by inoculating shrimp cheese spread with single cultures and then storing them at 37°C. Tubes inoculated with C. tyrobutyricum did not show any visible signs of growth (e.g., coagulation, discoloration, gas formation) in the cheese spread. After 2 weeks of incubation, tubes inoculated with C. cochlearium or C. sporogenes showed gas-holes, syneresis with separation of coagulated casein and liquid, and a change in color of the cheese. The amount of CO2 produced by C. cochlearium strains was approximately one-third that produced by the majority of C. sporogenes strains. To our knowledge, this is the first study to isolate and identify C. cochlearium as a spoilage organism in cheese spread.

Identification Method for Shallow Gas Layers in Cased Well

2014 ◽  
Vol 508 ◽  
pp. 146-149
Author(s):  
Xiao Min Tang ◽  
Xin Deng ◽  
Jian Fu ◽  
Lin Hou
Keyword(s):  
Gas Production ◽  
Production Testing ◽  
Neutron Lifetime ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Shallow Gas ◽  
Identification Methods ◽  
Identification Method ◽  
Gas Formation

In this paper, based on log response in gas formation, effective identification curves for shallow gas reservoirs are preferred from casedhole compensated neutron log, neutron lifetime log and openhole logs, and 4 parameters and 5 overlap curves are developed for identification of shallow gas reservoirs in cased wells. A gas reservoir in cased wells is interpreted with proposed identification methods. The gas production testing results shows that the proposed methods can determine shallow gas reservoirs in cased wells accurately.

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