Why is isobutyraldehyde supply so tight despite being a byproduct of butanol/octanol units?

Why is isobutyraldehyde supply so tight despite being a byproduct of butanol/octanol units?
Isobutyraldehyde is a byproduct of butanol/octanol (butyl-octyl alcohol) production, and capacity expansion is inherently limited because the main units are already oversupplied. Domestic downstream demand, however, has grown to roughly 740,000 t/yr against actual supply of only about 500,000 t/yr, leaving a structural gap of around 200,000 t. The supply base is highly concentrated among a few producers such as Luxi Chemical, Wanhua, Tianjin Bohai Yongli, and Shandong Jianlan. Intermittent plant turnarounds—like the Jiangsu Huachang shutdown or Tianjin units delaying conversion—quickly tighten spot availability. Because the product sits in a seller's market, even small supply losses trigger outsized price swings, as seen when prices surged past 17,000-18,000 yuan/t in 2021 and again approached 13,000 yuan/t in mid-2024.