微藻粗生物油催化加氢提质:外加氢源影响

Hydro-upgrading of crude algal bio-oil:Influence of external hydrogen sources

催化加氢是微藻粗生物油改性提质的有效途径,其中氢源是关键。探究了5种常规金属(铁、铝、锡、锌、镁)在超临界水条件下的产氢量,相同质量下铝的产氢量最大。在400℃、2 h条件下,以Ru/C为催化剂,以四氢萘为供氢介质对比了4种不同氢源(即微藻水热液化水溶物水热气化氢-M-HTL-H_(2)、小球藻水热气化氢-M-SCW-H_(2)、单质金属铝与水高温反应氢-Al-H_(2)及实验室氢-L-H_(2))对微藻水热液化所得粗生物油的加氢提质效果。结果表明,无论何种氢源,提质产物中提质油产率最高,其中L-H_(2)所得提质油产率最高(87.6%),而M-SCW-H_(2)所得提质油产率最低(70.4%)。4种氢源对粗生物油具有不同的加氢提质效果,其中Al-H_(2)对生物油的脱氧效果最好(93.03%),同时提质油热值最高(43.05 MJ/kg);M-SCW-H_(2)的脱氮效果最好(86.11%);4种氢源对生物油的脱硫效果均达到90%以上。氢源对提质油成分组成影响较大,L-H_(2)所得提质油中芳香烃和不饱和烃含量最高;M-HTL-H_(2)所得提质油中饱和烃含量最高,同时芳香烃含量最低。研究表明,采用不同外加氢源进行粗生物油加氢提质可获得不同生物油质提效果,如将不同氢源配伍有望获得更佳的生物质提质效果。

Catalytic hydrogenation is an effective way to improve the quality of crude algal bio-oil,in which hydrogen source is the key factor.The hydrogen production of five kinds of conventional metals(iron,aluminum,tin,zinc,magnesium)under supercritical water was investigated,and the hydrogen production of aluminum was the largest under the same mass.Then,using Ru/C as catalyst,the upgrading effect of four different hydrogen sources(hydrogen produced from hydrothermal gasification of microalgae hydrothermal liquefaction aqueous phase-M-HTL-H_(2),hydrogen produced from hydrothermal gasification of Chlorella M-SCW-H_(2),hydrogen produced from the reaction of Al and high temperature water-Al-H_(2),and laboratory elemental hydrogen-L-H_(2))on microalgae crude bio-oil in tetrahydronaphthalene medium was studied at 400℃and 2 h.The results show that,regardless of the hydrogen source,the upgraded bio-oil yield of the refined products is the highest,and the upgraded oil yield from L-H_(2) is the highest(87.6%),while the upgraded bio-oil yield from M-SCW-H_(2) is the lowest(70.4%).The four hydrogen sources also show different hydrogenation improvement effects on crude bio-oil,among which the deoxidation effect of Al-H_(2) on bio-oil is the highest(93.03%),and the calorific value of upgraded bio-oil is also the highest(43.05 MJ/kg).The nitrogen removal effect of M-SCW-H_(2) is the best(86.11%).The desulfuration effect of the four hydrogen sources on bio-oil is more than 90%.The hydrogen source also has a great influence on the composition of the upgraded bio-oil.The content of aromatic hydrocarbon and unsaturated hydrocarbon in the upgraded bio-oil obtained from L-H_(2) is the highest.The content of saturated hydrocarbon is the highest and the content of aromatic hydrocarbon is the lowest in the upgraded bio-oil obtained from M-HTL-H_(2).The results show that hydrorefining of crude bio-oil with different external hydrogenation sources can obtain different bio-oil quality improvement effects,and if these different hydrogen sources are combined,a better improvement in bio-oil quality can be obtained.