螺旋筛分侧面喂入式配丝装置在卷烟厂风力送丝中的应用

为解决风力送丝配丝过程中存在的烟丝分层和含末率较高等问题,进一步提高烟丝输送过程的控制精度和稳定性,进行了新型螺旋筛分侧面喂入式配丝装置的应用试验。结果表明,与改进前相比,配丝过程中的烟丝分层和烟末筛分问题得到了有效解决,烟丝结构明显改善,中短丝率提高2.41%;整丝率提高2.34%;碎丝率降低1.55%;填充值提高0.12cm3/g;烟支单重量标准偏差降低4mg/支;卷烟吸阻降低32Pa/支;端部落丝量平均降低1.23mg/支,烟支含末率平均降低0.42%;卷烟焦油量平均降低0.16mg/支;CO量平均降低0.28mg/支,感官质量稳定提高。     

O2, H2O or CO2 side-feeding policy in methane tri-reforming reactor: The role of influencing parameters

Methane tri-reforming is an efficient route to produce syngas. Distributing one component through a micro-porous membrane, namely side-feeding procedure, is an effective method for controlling reactions pathway and achieving the higher performance in membrane reactors. More recently, Alipour-Dehkordi and Khademi (2019) suggested a feasible and beneficial membrane multi-tubular reactor with O₂, H₂O or CO₂ side-feeding policy to describe the methane tri-reforming for producing a suitable syngas for the methanol and dimethyl ether direct synthesis processes. To complete the previous research, a theoretical study was presented to detect the role of effective parameters, including molar flow rate of feed components, membrane thickness, shell-side pressure, and inlet gas temperature on the H₂/CO ratio, CH₄ conversion, H₂ yield, and CO₂ conversion. Several results were observed, however one of the most attractive results was to achieve CO₂ conversion up to 40% in these configurations by controlling the influencing parameters (compared to CO₂ conversion in the conventional tri-reformer (i.e., 11.5%)); that would be favorable for the environment.     

Optimal design of methane tri-reforming reactor to produce proper syngas for Fischer-Tropsch and methanol synthesis processes: A comparative analysis between different side-feeding strategies

Assessment of the recent research on the side-feeding strategy in the methane tri-reforming reactor, suggests that this procedure can be a beneficial method for producing syngas. In the present study, special attention is given to the length of methane tri-reformer due to its significant effect on the residence time of distributed components, reaction pathways, synthesis gas production, and reactor performance in side-feeding procedures. The optimal design of three types of membrane tri-reforming reactor, containing O-MTR, H-MTR, and C-MTR, in which O₂, H₂O, and CO₂ permeate as the distributed reactants through the micro-porous membrane, respectively, as well as the conventional tri-reformer (MTR) was carried out to produce proper syngas for methanol and gas-to-liquid (GTL) units. The results show that the O-MTR offers the most advantages in terms of CH₄ conversion (i.e., 99.98%), H₂ yield (i.e., 1.91), and catalyst lifetime due to no formation of hot spot temperature. Additionally, the CH₄ conversion and H₂ yield in the O-MTR increased by 5% compared to the MTR. However, the length of these reactor structures to produce appropriate syngas for Fischer-Tropsch and methanol synthesis processes was in the following order: MTR < C-MTR $?$ O-MTR < H-MTR.     

Use of a micro-porous membrane multi-tubular fixed-bed reactor for tri-reforming of methane to syngas: CO2, H2O or O2 side-feeding

A one-dimensional heterogeneous model for four configurations of a reactor, three micro-porous membrane reactors with O₂ (O-MMTR), CO₂ (C-MMTR) or H₂O (H-MMTR) side-feeding strategy and one traditional reactor (i.e., multi-tubular fixed-bed reactor (MTR)), was developed to explain tri-reforming of methane to produce syngas. Effect of various side-feeding strategies on reactor performance containing CH₄ and CO₂ conversion, H₂/CO ratio, and H₂ yield was investigated under the same condition and then described by chemical species and temperature profiles. It was found that use of side-feeding strategies could be feasible, beneficial, and flexible in terms of change in membrane thickness and shell-side pressure for syngas production with H₂/CO = 2 which is proper for methanol and Fischer-Tropsch process, and = 1.2 which is suitable for DME direct synthesis. However, the syngas produced by the MTR is only appropriate for the methanol and Fischer-Tropsch synthesis under the base case conditions. Also, the results show that the micro-porous membrane reactors have higher CO₂ conversion, based on the H₂/CO = 1.2; so these strategies are more environmentally friendly compared to the traditional reactor.