中低煤阶煤的生物气生成特征

为得到中低煤阶煤的生物气生成特征,以龙口褐煤和淮南肥煤为产气母源进行生物气生成模拟试验,在控制其他影响因素相同的情况下,同时进行7组试验,其中6组试验组分别添加褐煤和肥煤样品为底物,通过统计和分析生物气的产气量、产气速率,探讨中低煤阶煤的生物气生成特征。结果表明:90 d的煤生物气生成模拟试验中,褐煤和肥煤试验组的生物甲烷气生成量和生气速率总体表现为煤阶越低,生气累积量和生气速率越大;在试验组生物气生成整体上经历了3个阶段:第一个阶段是迅速上升期,第二阶段是平稳下降期,第三阶段为趋于稳定期。但第一个阶段的不同煤阶煤样生气特征存在差异:淮南肥煤较龙口褐煤生气较早。生物气生成前期,生物产甲烷菌种主要以培养基中营养液为主要原料,生气速率较高,到生物气生成后期,生物产甲烷菌种消耗煤中有机质产气,从而导致生气速率降低。

Production of Mixed Alcohols from Bio-syngas over Mo-based Catalyst

A series of Mo-based catalysts prepared by sol-gel method using citric acid as complexant were successfully applied in the high efficient production of mixed alcohols from bio-syngas, derived from the biomass gasification. The Cu1Co1Fe1MO1Zn0.5-6%K catalyst exhibited a higher activity on the space-time yield of mixed alcohols, compared with the other Mobased catalysts. The carbon conversion significantly increases with rising temperature below 340 ℃, but the alcohol selectivity has an opposite trend. The maximum mixed alcohols yield derived from biomass gasification is 494.8 g/（kg catal·h） with the C2＋ （C2-C6 higher alcohols） alcohols of 80.4% under the tested conditions. The alcohol distributions are consistent with the Schulz-Flory plots, except methanol. In the alcohols products, the C2＋ alcohols （higher alcohols） dominate with a weight ratio of 70%-85%. The Mo-based cata- lysts have been characterized by X-ray diffraction and N2 adsorption/desorption. The clean bio-fules of mixed alcohols derived from bio-syngas with higher octane values could be used as transportation fuels or petrol additives.

Bio-methanol from Bio-oil Reforming Syngas Using Dual-reactor

A dual-reactor, assembled with the on-line syngas conditioning and methanol synthesis, was successfully applied for high efficient conversion of rich CO2 bio-oil derived syngas to bio-methanol. In the forepart catalyst bed reactor, the catalytic conversion can effectively adjust the rich-CO2 crude bio-syngas into the CO-containing bio-syngas using the CuZnA1Zr catalyst. After the on-line syngas conditioning at 450℃, the CO2/CO ratio in the blo- syngas significantly decreased from 6.3 to 1.2. In the rearward catalyst bed reactor, the conversion of the conditioned bio-syngas to bio-methanol shows the maximum yield about 1.21 kg/（kgcatarh） MeOH with a methanol selectivity of 97.9% at 260 ~C and 5.05 MPa using conventional CuZnA1 catalyst, which is close to the level typically obtained in the conventional methanol synthesis process using natural gas. The influences of temperature, pressure and space velocity on the bio-methanol synthesis were also investigated in detail.

Preparation of Bio-hydrogen and Bio-fuels from Lignocellulosic Biomass Pyrolysis-Oil

In recent years, production of engine fuels and energy from biomass has drawn much interest. In this work, we conducted a novel integrated process for the preparation of bio-hydrogen and bio-fuels using lignocellulosic biomass pyrolysis-oil （bio-oil）. The process includes （i） the production of bio-hydrogen or bio-syngas by the catalytic cracking of bio-oil, （ii） the adjustment of bio-syngas, and （iii） the production of bio-fuels by ole nic polymerization （OP） together with Fischer-Tropsch synthesis （FTS）. Under the optimal conditions, the yield of bio-hydrogen was 120.9 g H2/（kg bio-oil）. The yield of hydrocarbon bio-fuels reached 526.1 g/（kg bio-syngas） by the coupling of OP and FTS. The main reaction pathways （or chemical processes） were discussed based on the products observed and the catalyst property.

Life Cycle Cost of Electricity Generation from Biomass Gasifier

India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY （Rejiv Gandhi Grammen Vidyutikaran Yojana）, the rate of village electrification is much lower as household connectivity has been fairly low. The rest 15% villages and a larger proportion of households have to be electrified. Villages have been a major concern as cost of electrification is fairly high. The most favored alternative to any kind of users is generation of electricity from diesel generating sets and renewable sources of energy. But the capital cost of renewable energy equipments is fairly high. Gradually, there is a reduction in the prices of these systems due to availability of better technological options and they are becoming competitive to grid electricity. In this paper, an attempt has been made to calculate the cost of production of electricity from stand-alone, off-grid devices biomass gasifiers （both dual fuel and pure gas type） and compare with that of diesel generating sets by using the concept of LCC （life cycle costing） and Homer software. It is found that the cost of per unit electricity generation （kWh） has been always the lowest in comparison to diesel generating sets even if the price of biomass increases to some extent.

The origin mechanism of coalbed methane in the eastern edge of Ordos Basin

In the eastern edge of the Ordos Basin,the coalbed methane(CBM)development has not made substantial progress in the past20 years,and the origin of gas can be used to guide the CBM block-selecting and development.Based on the 37 sets of carbon isotope data,the origin of the gas was determined and the origin mechanism was studied in this work.The 13CPDB of methane ranges from 70.5‰to 36.19‰in the eastern edge in the Ordos Basin and the value becomes heavier from the north to the south.The secondary biogenic gas and the thermogenic gas are mixed in the shallow area and the thermogenic gas occurs in the medium and deep levels.The phenomenon is controlled mainly by the distribution of coal rank and hydrodynamics.Firstly,based on the relationship between China coal rank and methane 13CPDB,the medium rank coal is dominant in the eastern edge of the Ordos Basin,and the mixture of the secondary biogenic gas and the thermogenic gas is formed in the coal of vitrinite reflectant ratio(Rmax)between 0.5%and 2.0%if there is appropriate hydrodynamics;at the same time,because of the shallow burial depth,and the well-developed coal outcrop,meteoric water and other surface water carrying bacteria recharge the coal reservoir,metabolize the organic compounds at a relatively low temperature,and generate methane and carbon dioxide.Wherever the trapping mechanisms occur in the coal,such as Liulin and Hancheng,modern gas content should be high.