Integration of dual fluidized bed steam gasification into the pulp and paper industry

The pulp and paper industry represents an industry sector which is characterised by its already high degree of sustainability. Biomass is a renewable input material, and typically highly developed recovery cycles minimise the loss of chemicals used in the pulping process. However, certain parts of the recovery cycle are still operated on fossil fuels. This study deals with the substitution of the fossil-based gaseous fuel with product gas from biomass gasification.Gasification experiments have shown that bark available at pulp and paper mills is suitable to produce a product gas via dual fluidised bed steam gasification as a promising substitute for natural gas. Based on the comparison of process layouts regarding the separation of non-process elements, separation efficiency is derived for different setups. To ensure operational security of the chemical recovery cycle, comprehensive gas cleaning including heat exchangers, a particle filter, and a liquid scrubber unit is advised. The gas flow of fuel gas into the gas burner is increased as the heating value of the product gas is accordingly lower in comparison to natural gas. Furthermore, adaptions of the gas burner might be necessary to address the earlier ignition of the H2-rich product gas compared to natural gas.

CO2 Adsorption and Desorption by Waste Ion-Exchange Resin–Based Activated Carbon on Fixed Bed

The waste ion-exchange resin–based activated carbon (WIRAC) was utilized for CO2 adsorption. The effect of adsorption temperature, gas flow, CO2 concentration, and adsorbent filling content on CO2 adsorption properties of WIRAC and the effect of desorption temperature and sweep gas flow on CO2 desorption performances of WIRAC were researched. In the adsorption process, with the increase of adsorption temperature, the CO2 adsorption capacity and adsorption rate decrease; as the gas flow increases, the CO2 adsorption capacity decreases, but the adsorption rate increases; with the increase of CO2 concentration and adsorbent filling content, the CO2 adsorption capacity and adsorption rate both increase. In the desorption process, the higher the desorption temperature and the smaller the sweep gas flow, the higher the CO2 purity of product gas and the longer the desorption time. In order to make sure the adsorbent be used efficiently and the higher CO2 concentration of product gas, the adsorption and desorption conditions selected should be a suitable choice.

Pengaruh Temperatur Pada Microwave Pirolisis Cangkang Kelapa Sawit dan Low Density Polyethylene Dengan Katalis Zeolite/Kalsium Oksida

In general, the use of oil palm parts can be utilized by industry, but it is different from oil palm shells which become waste. The high use of plastic is proportional to the waste generated. So far, both types of waste are problems that have not been resolved. The utilization of waste shell waste and low-density polyethylene using the pyrolysis method. Microwave technology has been widely used as a heat source in the pyrolysis process. The advantages of using microwaves in pyrolysis are fast and selective heating, efficient energy use, and control of pyrolysis products. This study aimed to determine the characteristics of Pyrolytic-oil from the pyrolysis of waste oil palm shells and Low-density polyethylene. The research was conducted using a microwave with temperature variations of 400oC, 450oC, 500oC, 550oC and 600oC. The composition of the main ingredients consisted of 75 grams of palm shells, 75 grams of low-density polyethylene plastic, 56.25 grams of a zeolite catalyst, 56.25 grams of calcium oxide and 131.25 grams of charcoal carbon absorber. The results showed the effect of temperature on pyrolytic-oil productivity; as the temperature increases, the product gas increases. The lowest density value at a temperature of 400oC is 966.8 Kg/m. The lowest viscosity at a temperature variation of 500oC is 2.1 Mpa.s. The highest acidity value is at a temperature of 550oC.

Steam gasification of municipal solid waste for hydrogen production using Aspen Plus® simulation

Approximately 50 million ton of municipal waste is generated in Pakistan per annum and most of this waste does not reach final deposit sites. In this research, Silvia gas technology for municipal solid waste (MSW) steam gasification is studied to produce high energy density product gas. A detailed simulation model is developed with the help of Aspen Plus®. Catalyst coal bottom ash along with lime (CaO) as sorbent is employed for tar reduction and improving the hydrogen (H2) yield in the product gas. The effect of gasification operating temperature and the ratio of steam to feedstock on synthetic gas composition, hydrogen (H2) yield and heating values of synthesis gas was studied. Coal bottom ash along with CaO had a substantial effect on hydrogen (H2) yield and synthesis gas production. Rise in steam–MSW ratio increased the hydrogen (H2) from 58 to 74.9% (vol.). The maximum value of hydrogen (H2) production, i.e., 74.9% by vol. was achieved at a steam–feedstock ratio of 1.9. A maximum of 79.8% by vol. hydrogen (H2) was attained at 680 °C gasification operating temperature with 1.3 ratio of steam to feedstock and coal bottom ash 0.07% by wt. High value of 13.1 MJ/Nm3 of hydrogen-rich synthetic gas was achieved at 680 °C. The acquired results lay the foundation for the economic feasibility study and pilot plant for MSW usage for hydrogen production.

Catalytic Tar Conversion in Two Different Hot Syngas Cleaning Systems

Tar in the product gas of biomass gasifiers reduces the efficiency of gasification processes and causes fouling of system components and pipework. Therefore, an efficient tar conversion in the product gas is a key step of effective and reliable syngas production. One of the most promising approaches is the catalytic decomposition of the tar species combined with hot syngas cleaning. The catalyst must be able to convert tar components in the synthesis gas at temperatures of around 700 °C downstream of the gasifier without preheating. A Ni-based doped catalyst with high activity in tar conversion was developed and characterized in detail. An appropriate composition of transition metals was applied to minimize catalyst coking. Precious metals (Pt, Pd, Rh, or a combination of two of them) were added to the catalyst in small quantities. Depending on the hot gas cleaning system used, both transition metals and precious metals were co-impregnated on pellets or on a ceramic filter material. In the case of a pelletized-type catalyst, the hot gas cleaning system revealed a conversion above 80% for 70 and 110 h. The catalyst composed of Ni, Fe, and Cr oxides, promoted with Pt and impregnated on a ceramic fiber filter composed of Al2O3(44%)/SiO2(56%), was the most active catalyst for a compact cleaning system. This catalyst was catalytically active with a naphthalene conversion of around 93% over 95 h without catalyst deactivation.

Hydrogen rich product gas from air-steam gasification of Indian biomasses with waste engine oil as binder

Present study concerns with the production of H2 rich product gas by thermochemical energy conversion having biomass gasification as a route for the four biomasses i.e., Kasai Saw Dust, Lemon Grass, Wheat Straw and Pigeon Pea Seed Coat. The biomasses are from the family of woody biomass, grasses, agricultural waste and food process industry wastes. Waste engine oil as an additive is used, which also acts as a binder. Air gasification and Air-steam gasification is applied and compared for product gas composition, hydrogen yield and other performance parameters like lower heating value, energy yield. Product gas constituents, hydrogen production is examined with different steam to biomass ratio (S/B ratio) and equivalence ratio. The equivalence ratio varies from 0.20–0.40 and the steam to biomass ratio varies between 0–4. The waster engine oil is mixed with the biomasses with different percentage of 5 and 10 wt%. For enhancement of feedstock quality palletization process is applied. The H2 yield is greatly affected by the equivalence ratio. Results show maximum H2 production and higher calorific value of product gas at an air to fuel of 0.26 for all the biomass pallets. Also, the S/B ratio observed as important aspect for hydrogen enrichment. Hydrogen yield is maximum at 2.4 steam to biomass ratio. This study considers the rarely studied Indian biomasses with waste engine oil as an additive for hydrogen-rich product gas production and will be beneficial for small scale hydrogen-rich syngas production considering the central Indian region originated biomasses. Statement of Novelty (SON): Research work belongs to eco-friendly use of rarely studied Indian biomass pallets. Equivalence air to fuel ratio (E/R ratio), steam to biomass ratio (S/B ratio) and waste engine oil as additive have been considered to upgrade H2 content and Calorific Value (CV) of the product gas. Novelty of work include use of waste engine oil as additive to make biomass pallets.

Combining Dual Fluidized Bed and High-Temperature Gas-Cooled Reactor for Co-Producing Hydrogen and Synthetic Natural Gas by Biomass Gasification

Biomass gasification to produce burnable gas now attracts an increasing interest for production flexibility in the renewable energy system. However, the biomass gasification technology using dual fluidized bed which is most suitable for burnable gas production still encounters problems of low production efficiency and high production cost. Here, we proposed a large-scale biomass gasification system to combine dual fluidized bed and high-temperature gas-cooled reactor (HTR) for co-production of hydrogen and synthetic natural gas (SNG). The design of high-temperature gas-cooled reactor biomass gasification (HTR-BiGas) consists of one steam supply module to heat inlet steam of the gasifier by HTR and ten biomass gasification modules to co-produce 2000 MWth hydrogen and SNG by gasifying the unpretreated biomass. Software for calculating the mass and energy balances of biomass gasification was developed and validated by the experiment results on the Gothenburg biomass gasification plant. The preliminary economic evaluation showed that HTR-BiGas and the other two designs, electric auxiliary heating and increasing recirculated product gas, are economically comparative with present mainstream production techniques and the imported natural gas in China. HTR-BiGas is the best, with production costs of hydrogen and SNG around 1.6 $/kg and 0.43 $/Nm3, respectively. These designs mainly benefit from proper production efficiencies with low fuel-related costs. Compared with HTR-BiGas, electric auxiliary heating is hurt by the higher electric charge and the shortcoming of increasing recirculated product gas is its lower total production. Future works to improve the efficiency and economy of HTR-BiGas and to construct related facilities are introduced.