Utilization of rice husk–sawdust as blending feedstock of small-scale downdraft gasifier

Synthetic gas generated from the gasification of biomass feedstocks is one of the clean and sustainable energy sources. In this work, a fixed-bed downdraft gasifier was used to perform the gasification on a lab-scale of rice husk, sawdust, and coconut shell. The aim of this work is to find and compare the synthetic gas generation characteristics and prospects of sawdust and coconut shell with rice husk. A temperature range of 650–900 °C was used to conduct gasification of these three biomass feedstocks. The feed rate of rice husk, sawdust, and coconut shell was 3–5 kg/h, while the airflow rate was 2–3 m3/h. Experimental results show that the highest generated quantity of methane (vol.%) in synthetic gas was achieved by using coconut shell than sawdust and rice husk. It also shows that hydrogen production was higher in the gasification of coconut shell than sawdust and rice husk. In addition, emission generations in coconut shell gasification are lower than rice husk although emissions of rice husk gasification are even lower than fossil fuel. Rice husk, sawdust, and coconut shell are cost-effective biomass sources in Bangladesh. Therefore, the outcomes of this paper can be used to provide clean and economic energy sources for the near future.

Download Full-text

Shifting of the flame front in a small-scale commercial downdraft gasifier by water injection and exhaust gas recirculation

Fuel ◽

10.1016/j.fuel.2021.121297 ◽

2021 ◽

Vol 303 ◽

pp. 121297

Author(s):

A. Zachl ◽

M. Buchmayr ◽

J. Gruber ◽

A. Anca-Couce ◽

R. Scharler ◽

...

Keyword(s):

Flame Front ◽

Water Injection ◽

Exhaust Gas Recirculation ◽

Small Scale ◽

Exhaust Gas ◽

Downdraft Gasifier ◽

Gas Recirculation

Download Full-text

Effect of tuyer distance above grate on propagation front and performance of downdraft gasifier with the feedstock of rice husk

Renewable Energy ◽

10.1016/j.renene.2018.11.110 ◽

2019 ◽

Vol 134 ◽

pp. 1034-1041 ◽

Cited By ~ 1

Author(s):

A.A.P. Susastriawan ◽

Harwin Saptoadi ◽

Purnomo

Keyword(s):

Rice Husk ◽

Downdraft Gasifier ◽

Propagation Front ◽

And Performance

Download Full-text

Environmental and economic potential of rice husk use in An Giang province, Vietnam

Journal of Vietnamese Environment ◽

10.13141/jve.vol8.no3.pp206-211 ◽

2017 ◽

Vol 8 (3) ◽

pp. 206-211

Author(s):

Thi Mai Thao Pham

Keyword(s):

Power Generation ◽

Rice Husk ◽

Life Cycle Analysis ◽

Large Scale ◽

Fossil Fuels ◽

Small Scale ◽

Emission Mitigation ◽

Mitigation Potential ◽

Direct Combustion ◽

The Cost

To evaluate CO2 emission mitigation potential and cost effectiveness of rice husk utilization, Life Cycle Analysis was conducted for 9 scenarios. The results showed that, gasification is the most efficient CO2 mitigation. From cost analysis, the cost mitigation can be achieved by replacing the current fossil fuels in cooking scenarios. Among the power generation scenarios, it was found that 30MW combustion and 5MW gasification power generations were the most economically-efficient scenarios. The briquette combustion power generation appeared less cost-competitive than direct combustion, whilst the large-scale gasification scenarios and the pyrolysis scenarios give the increase in cost from the baseline. From the viewpoints of both CO2 and cost, it was indicated that the win-win scenarios can be the rice husk use for cooking, for large-scale combustion power generation, and for small-scale gasification. Để đánh giá tiềm năng giảm thiểu phát thải CO2 và hiệu quả chi phí của việc sử dụng trấu, phương pháp đánh giá vòng đời sản phẩm đã được thực hiện cho 9 kịch bản. Kết quả cho thấy, khí hóa trấu để sản xuất điện có tiềm năng giảm phát sinh khí CO2 nhiều nhất. Kết quả phân tích chi phí cho thấy việc giảm thiểu chi phí có thể đạt được khi thay thế sử dụng nhiên liệu hóa thạch trong kịch bản dùng trấu cho nấu ăn. Giữa các kịch bản về sản xuất điện, hiệu quả kinh tế cao nhất trong trường hợp đốt trực tiếp trấu để sản xuất điện ở quy mô công xuất lớn (30MW) và khí hóa ở quy mô trung bình (5MW). Trường hợp dùng củi trấu không mang lại hiệu quả kinh tế so với dùng trực tiếp trấu để phát điện. Hai trường hợp dùng trấu để sản xuất dầu sinh học và khí hóa gas công suất lớn (30MW) cho thấy chi phí tăng cao so với điều kiện biên. Kịch bản cho kết quả khả thi về hiệu quả kinh tế và giảm phát thải CO2 là dùng trấu để nấu ăn, đốt trực tiếp để phát điện công suất lớn và khí hóa công suất trung bình.

Download Full-text

Manurial amendments and source of water for supplemental irrigation of sawah-rice system influenced soil quality and rice yield

Agro-Science ◽

10.4314/as.v20i1.15 ◽

2021 ◽

Vol 20 (1) ◽

pp. 95-102

Author(s):

A.L. Nnadi ◽

V.U. Ugwu ◽

J.C. Nwite ◽

S.E. Obalum ◽

C.A. Igwe ◽

...

Keyword(s):

Rice Husk ◽

Rice Husk Ash ◽

Spring Water ◽

Mineral Fertilizers ◽

Small Scale ◽

Rice Grain ◽

Southeastern Nigeria ◽

Supplemental Irrigation ◽

Husk Rice ◽

Poultry Droppings

Soil and water management research on adapting the promising sawah ecotechnology for lowland rice farming in West Africa has largely focused on the abundant inland valleys; floodplains which too represent a huge agricultural resource in the region have not been so involved. Sawah refers to a bunded, puddled and leveled basin for rice, with water inlets and outlets for irrigation and drainage, respectively. In conventional sawah, soil fertility is augmented using mineral fertilizers, with an option to harness lowland water resources for use in small-scale irrigation to create the so-called sawah typologies. In this study, we evaluated the effects of three manurial amendments (rice husk, rice-husk ash and poultry droppings, each at 10 t ha–1) and NPK 20:10:10 at 400 kg ha–1 interacting with source of water (spring or pond) used for supplemental irrigation of three sawah typologies in a floodplain in southeastern Nigeria. Plots amended with poultry droppings and supplemented with spring water recorded the overall best performance of the sawah-rice system; the control being the unamended non-supplemented (solely rainfed) plots recorded the worst. Rice-husk ash and rice husk enhanced soil pH and soil organic carbon, respectively. The three sawah typologies showed a consistent trend thus spring-supplemented ≥ pond-supplemented ≥ non-supplemented sawah. Rice grain yield was influenced by soil total nitrogen and the sum of the three plant-nutrient basic cations (K+ , Ca2+ and Mg2+), with the influence of K+ alone being the greatest. To enhance rice performance including grain yields in floodplain sawah, farmers should utilise poultry droppings as soil manure and spring water for supplemental irrigation.

Download Full-text

Analysis and Comparison of Biochar From Pilot Scale Downdraft Gasifier

Volume 6A: Energy ◽

10.1115/imece2015-52444 ◽

2015 ◽

Author(s):

Tejasvi Sharma ◽

Yunye Shi ◽

Guiyan Zang ◽

Albert Ratner

Keyword(s):

Large Scale ◽

Pilot Scale ◽

Proximate Analysis ◽

Small Scale ◽

Volatile Components ◽

Composition Analysis ◽

Reduction Zone ◽

Downdraft Gasifier ◽

Porosity Analysis ◽

Corn Grains

Gasification is incomplete combustion of solid fuel that results in the production of vapor, often referred to as syngas or producer gas, char, and tar. When this process is applied to biomass, the resulting char, referred to as biochar, is produced and has been shown to enhance soil fertility and crop growth. As part of a broader effort, this work examines how the gasification process impacts the biochar generated through downdraft gasification. In contrast to previous publications, which only focused on the syngas compositions, this research paper expands the analysis to the composition of the biochar produced in the gasification systems. In a large-scale gasifier, corn grains at about a 15% moisture level are inserted into a pilot scale downdraft gasifier from the top. In this system, both air and fuel move in the same direction. The air entering the setup is controlled using a damper. Corn grains entering the gasifier pass through a drying zone where the moisture content in it is removed. The dry corn then passes through a combustion and pyrolysis zone, followed by a reduction zone. The high temperature present at the bottom in the reduction zone cracks any tar present in the syngas produced. This syngas exits from the bottom of the gasifier. The char produced has a residence time from half an hour to several hours. About 20% of the fuel that’s inserted in the gasifier is converted to biochar. An ultimate and proximate chemical composition analysis, BET porosity analysis, and an SEM image analysis were carried out on the biochar produced from this system. From the SEM analysis, a surface area of 2.38 m2/g was obtained. From the ultimate and proximate analysis, it was observed that the biochar had higher carbon content and a lack of volatile components compared to other reported biochars and levels similar to activated carbon. From the BET porosity analysis, both small scale and large-scale pores were observed but quantified comparison with other biochar is still on going. Porosity is known to be an important factor in biochar effectiveness as a soil amendment.

Download Full-text