Catalytic hydroisomerization of n-paraffin aims to produce branched paraffin isomers and suppress cracking reactions in the production of the low cloud point of biodiesel. The development of the type of metal and catalyst support, amount of metal loading, and reaction conditions are important to increase the catalyst activity. A high performace catalyst for hydroisomerization bears bifunctional characteristics with a high level of hydrogenation active sites and low acidity, maximizing the progress of hydroisomerization compared to the competitive cracking reaction. In addition, a catalyst support with smaller pore size can hinder large molecular structure isoparaffins to react on the acid site in the pore thus providing good selectivity for converting n-paraffin. Catalysts loaded with noble metals (Pt or Pd) showed significantly higher selectivity for hydroisomerization than non-noble transition metals such as Ni, Co, Mo and W. The reaction temperature and contact time are also important parameters in hydroisomerization of long chain paraffin, because long contact times and high temperatures tend to produce undesired byproducts of cracking. This review reports several examples of supported metal catalyst used in the hydroisomerization of long chain hydrocarbon n-paraffins under optimized reaction conditions, providing the best isomerization selectivity results with the lowest amount of byproducts. The role of various metals and their supports will be explained mainly for bifunctional catalysts.
The COVID-19 pandemic has impacted the seaweed industry and business. The export-import trade is the most severely impacted sector, mainly the raw material export of seaweed. The purpose of this study was to determine how smallholder farmers in West Nusa Tenggara, Indonesia, can survive under adverse conditions and maintain their businesses during a pandemic. The research was conducted through a combination of field surveys and in-depth interviews with respondents. Interviews were performed using a variety of instruments, including questionnaires and cameras. According to the study's findings, smallholder farmers are impacted by a decline in prices and demand. Smallholder farmers in West Nusa Tenggara, Indonesia, are attempting to adapt or adjust their operations to maintain profitability. Seaweed farmers make significant savings and cut their spending in the event of a pandemic. What is intriguing is that respondents did not reduce their spending on food. Instead, they prioritize reducing tertiary needs. Additionally, the same holder farmer borrows from collectors, borrows from the bank, and works side jobs. Thus, seaweed farmers are relatively unaffected by this pandemic and recover more quickly than other types of fishery businesses.Keywords: Covid 19, seaweed, smallholder farmer, Nusa Tenggara Barat
Microplastics have been found in Indonesian seas from surface to sediments with varying amounts, sizes and shapes. Microplastics in surface and sediments can negatively affect biota. Microplastic can stick to the surface and enter the marine biota through direct consumption, inhalation, and trophic transfer. A number of approaches have been proposed to deal with the plastic debris. This includes combustion, thermal degradation, biodegradation and photocatalysis. A nanostructure photocatalyst can be an environmentally friendly way to fix the problem of plastic debris. Metals can catalyze dissociation of hydroperoxides and increase oxidative cutting of polyolefins. In this review, we want to assess the feasibility of metal oxides as photocatalysts for plastic degradation, especially in seawater. Metal oxides can catalyze plastic degradation and form several compounds along the chain, such as hydroxyl (alcohol), peroxide, carbonyl groups, esters, and low molecular weight molecules. In general, metal oxide modification can increase the effectiveness of the plastic degradation photocatalytic process.
Moluska memiliki cara unik dalam mempertahankan dirinya pada daerah intertidal, selain itu moluska di daerah ini memiliki keanekaragaman yang berbeda dibandingkan zona lainnya. Oleh karena itu, perlu kajian mendalam terkait keanekaragaman dan cara adaptasi moluska pada daerah tersebut. Tujuan dari penelitian ini adalah untuk mengetahui jenis dan keanekaragaman moluska, cara adaptasi moluska pada gelombang tinggi, potensi ekonomis moluska, serta menentukan klaster komunitas moluska di Pantai Pamengpeuk, Jawa Barat. Penelitian ini berlokasi di Pantai Bubujung, Pantai Karang Paranje, Pantai Santolo Indah, Pantai Karang Papak, Pantai Taman Manalusu, Pantai Cicalobak, Pantai Karang Wangi, Pantai Ranca Buaya 2 dan Pantai Ranca Buaya 1 dengan menggunakan metode purposive sampling. Hasil pengamatan ditemukan 37 spesies moluska yang terdiri dari 33 jenis gastropoda dan 4 jenis bivalvia. Moluska di daerah ini beradaptasi dengan cara bersembunyi pada bebatuan dan mencari daerah yang lembab untuk mempertahankan kadar air di dalam tubuhnya. Famili dengan jumlah individu dan penyebaran tertinggi adalah Nodilittorina, Trochoides, dan Littorinidae. Indeks keanekaragaman (H') moluska tertinggi yaitu Pantai Ranca Buaya 1 dengan indeks keanekaragaman 2,8, sedangkan indeks kemerataan tertinggi (e) yaitu Pantai Parenje (0,92). Moluska yang berpotensi ekonomis untuk dikembangkan di Pantai Pamengpeuk, Garut Selatan antara lain Planaxis sulcata, Nerita polita, Nerita picea, Cerithium eburneum, dan Turbo setosus. Pantai Pemengpeuk memiliki tingkat keanekaragaman yang tinggi sehingga berpotensi untuk dikembangkan dalam rangka meningkatkan kelestarian dan perekonomian masyarakat di wilayah tersebut.
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